Your Maximum Heart Rate (MHR) is the highest number of beats per minute your heart can reach during maximum physical exertion. While the most accurate way to find your MHR is through a clinical stress test, mathematical formulas provide a very close estimate for most healthy adults.
This calculator uses three primary scientific formulas to provide you with the most accurate estimate:
Fox Formula (220 – Age): The most common formula used for general fitness.
Tanaka Formula (208 – 0.7 × Age): Research suggests this is more accurate for individuals over the age of 40.
Gulati Formula (206 – 0.88 × Age): A specialized formula specifically developed for women's cardiovascular health.
Understanding Your Heart Rate Zones
Once you know your Max HR, you can divide your training into specific zones to target different fitness goals:
Zone 1: Very Light (50-60%) – Best for warm-ups, cool-downs, and active recovery. Improves overall health and helps recovery after harder sessions.
Zone 2: Light (60-70%) – Known as the "Fat Burn Zone." This intensity builds aerobic endurance and allows the body to become efficient at burning fat as fuel.
Zone 3: Moderate (70-80%) – The "Aerobic Zone." This improves blood circulation and increases lung capacity. This is the sweet spot for improving cardiovascular fitness.
Zone 4: Hard (80-90%) – The "Anaerobic Zone." Here, your body begins to produce lactic acid. This training increases your speed and metabolic rate.
Zone 5: Maximum (90-100%) – "Red Line" territory. Only sustainable for very short durations. Used by athletes to improve peak performance and explosive power.
Practical Example
Imagine a 40-year-old male. Using the Tanaka formula:
For this individual, a Zone 2 (Fat Burn) workout would require keeping the heart rate between 108 and 126 BPM (60% to 70% of 180).
Important Safety Note
Heart rate formulas provide statistical averages. Factors such as medications (like beta-blockers), caffeine intake, stress, and underlying health conditions can significantly alter your actual maximum heart rate. Always consult with a physician before starting a new intensive exercise program.
function calculateMaxHR() {
var age = document.getElementById('userAge').value;
var gender = document.getElementById('userGender').value;
if (!age || age 115) {
alert("Please enter a valid age.");
return;
}
age = parseFloat(age);
var foxHR = 220 – age;
var tanakaHR = 208 – (0.7 * age);
var gulatiHR = 206 – (0.88 * age);
var finalMaxHR = 0;
var formulaNote = "";
// Selection Logic: Tanaka for everyone, but Gulati specifically for women as it's often more accurate
if (gender === 'female') {
finalMaxHR = Math.round(gulatiHR);
formulaNote = "Calculated using the Gulati Formula (optimized for women).";
} else {
if (age > 40) {
finalMaxHR = Math.round(tanakaHR);
formulaNote = "Calculated using the Tanaka Formula (optimized for adults 40+).";
} else {
finalMaxHR = Math.round(foxHR);
formulaNote = "Calculated using the standard Fox Formula (220 – age).";
}
}
document.getElementById('maxHRVal').innerText = finalMaxHR;
document.getElementById('formulaUsed').innerText = formulaNote;
// Calculate Zones
var zones = [
{ name: "Zone 1 (Very Light)", intensity: "50-60%", min: 0.50, max: 0.60, class: "zone-1" },
{ name: "Zone 2 (Light)", intensity: "60-70%", min: 0.60, max: 0.70, class: "zone-2" },
{ name: "Zone 3 (Moderate)", intensity: "70-80%", min: 0.70, max: 0.80, class: "zone-3" },
{ name: "Zone 4 (Hard)", intensity: "80-90%", min: 0.80, max: 0.90, class: "zone-4" },
{ name: "Zone 5 (Max)", intensity: "90-100%", min: 0.90, max: 1.00, class: "zone-5" }
];
var zonesHTML = "";
for (var i = 0; i < zones.length; i++) {
var minBpm = Math.round(finalMaxHR * zones[i].min);
var maxBpm = Math.round(finalMaxHR * zones[i].max);
zonesHTML += "